Dual automatic intermitting unit



July 13, 1943. w. BRAUER DUAL AUTOMATIC INTERMITTING UNIT Filed June 2, 1941 3 Sheets-Sheet l July 13, 1943. w. BRAUER DUAL AUTOMATIC INTERMITTING UNIT Filed June 2, 1941 3 Sheets-Sheet 2 ATTORNEY July 13, 1943. w. BRAUER 2,324,355

DUAL AUTOMATIC INTERMI-TTING UNIT Filed June 2, 1941 3 sheets-sheet 5 l I//A\\ /V l Z'alier ralzer mvENToR KM-M ATTOR N EY Patented July 13,' 1943 UNITED STATES PATNT GFFICE DUAL AUTOMATIC QJ'TEENITETNG UNIT Walter Brauer, Oklahoma City, lila.

Application June 2, 1941, Serial No. 3%,263

10 Claims. Clf103-Z6i) This invention relates to the flowing of liquid from wells and more particularly, but not by way of limitation for separation of the liquifiable constituents from a liquid having a high gas-oil ratio, and to the automatic intermitting apparatus for controlling the emission of motive fluid pressure for raising the liquid out of the well. This application is a continuation in part of my co-pendingapplication, Serial No. 378,284, led February l0, 1941.

n the production of oil from wells having an uents upon becoming condensed fall back into -f the lowermost portion of the well, which in conjunction with the liquid flowing from the oil bearing strata, forms a hydrostatic head of liquid capable of being lifted from the Well.

In present day production of oil in most oil producing states the use of motive pressure gas for lifting or displacing oil from the well hole has given rise to the practicability of automatic intermitting systems. Heretofore fluid actuated pumps or gas controlled diierential valves have given little consideration to the oil or sand pressure of the well in that motive iluid pressure for kthe lifting apparatus has been directed from the well surface and allowed to be forced against the well sand, thus having a tendency to oppose the normal lift of well liquid flowing from the formation. Furthermore, the use of mechanical devices such as springs, bellows and the like has given little consideration to the volume of liquid to be lifted relative to an efficient gas-oil ratio by utilizing the proper amount of gas for displacing a predetermined volume of oil.

It is therefore an important objectjof this invention to provide means for -liftingliquids rom a Well which are so constructed and operated as to prevent placing a pressure on theiwell formation sand which would cause recession of the liquids desired to be lifted.

Another object of this invention is to provide an automatic intermitting device which will allow expansion of gases created by the sand pressure of the well to allow a condensation of the liquiliae ble constituents in the gases, and lifting the condensates through the medium of motive uid pressure entering the eduction tubing in predetermined quantities responsive to changes in the condensate level standing in the well. y A further object of this invention is to provide an automatic intermitting apparatus for motivev fluid lifting of liquid `from a well which reduces the gas-oil ratio and provides a greater eiliciency in the use of the motive uid energy.

Another object of this invention is to intermittently gas lift oil vfrom wells by introducing or jetting into the oil a motive fluid pressure and controlling the same automatically by a valve operated and controlled by a float cylinder re?. sponsive to the height of the liquid level standing in the well, said liquid level partially created by a condensation of liquiable constituents from the Well gas expanded in the well. And still another object of this invention is to intermittently displace oil from a well by motive fluid pressure automatically injected by va Valve which in turn is operated and controlled by a float cylinder responsive to the height of the liquid level to be lifted wherein the liquid acts as a stopper for a float cylinder actuating thevalve to allow the input fluid to provide buoyant characteristics to the cylinder causing it to move vertically in actuation of the valve. Other objects and advantages of the invention will be evident from the following detailed description read in conjunction with the accompanying drawings which illustrate one form of my invention. l

In the drawings: Fig. 1 is al fragmentary vertical sectional View of the uppermost sections of the tubing shown disposed in the Well casing and having certain parts in elevation and showing the inlet means for the motive fluid. I A

Fig. l-A is a view similar to Fig. 1 showing the disposition of the automatic'intermitting unit. Fig. y14n is a similar View showing the dispo"- sition of thetubing catcher and the motive fluid outlet nozzle. Fig. l-C is a similar View showingthe'lower'- most sections of the` well tubing and the arrange# ment of the control and choke valves therein. Fig. 2 is a'vertical elevational View ofthe liquid liftingl'apparatus shown disposed in a well hole. Fig. 3 is a View taken on lines 3-3 of Fig. 1-B. 4 is a View taken on lines of Fig. l-A. Fig. 5 is a view taken on lines 5 5 of Fig. 1-A. Fig. 6 is an enlarged detailed sectional view of one ci" the check valves.

Referring to the drawings in detail land more particularly to Figs. 1 through l-C inclusive, reference character 2 designates a string of casing suspended in an oil well hole. A string of tubing 4 is arranged in spaced relation to the casing 2 and extends through the length of the well. A string of smaller sized pipe or tubing 6 (preferably 1/4 inch.) is disposed in the spa-ce 8 between the tubing and the casing. A plurality of clamps I are vertically spaced along the string of tubing 4 for anchoring the smaller tubing 6 in the space B. In the uppermost portion of the apparatus, tubing sections 4 are coupled together by a collar l2 having outwardly protruding or flanged portion 4 provided with a threaded aperture I6 for receiving an inlet check valve I8 of the ball type shown in detail in Fig. 6.

Below the coupling I2 the sections of tubing 4 are coupled by a collar 20 and an apertured nut 2| to which is threaded a Valve cage 22 encircling a ball valve 24 cooperating with a seat 26 seated on the nut 2|. The valve acts as a check against the inlet motive fluid or as an outlet valve for the lifted oil as will be hereinafter set forth.

Sections of tubing 4 extend into threaded engagement at 28 (Fig. l-A) with a collar 30 substantially H-shaped (in cross section). Interposed in the tubing lbetween the nut 2| and the collar 30 is an auxiliary valve unit A which will be hereinafter explained. The collar 30 is constructed to contain the automatic intermitting Valve unit B which will be hereinafter referred to. The smaller tubing 6 extends through space 8 into communication with a longitudinal port 34 of the collar 30.

Sections of the tubing 4 extend below thecolla-r 30 into threaded engagement with a collar 36 (Fig. l-B) which in turn receives a nut 38. The smaller tubing 6 extends downward rfrom a longitudinal port 40 in collar 30 into engagement with a longitudinal port 42 in collar 35, said port 42 in turn communicates with a radial port 44 in nut 38. A section of the tubing 4 is threaded at 46 to nut 38 and extends downwardly therefrom. The small pipe 6 communicates with port 44 by being disposed in a threadedv bore 48 of nut 38, and from this point downward it is disposed in the interior of the tubing 4.

From Fig. 3 it will be noted that the nut 38 is constructed with substantially semi-circular apertures or ports 50 acting as outlet or'upflow ports for the lifted liquid as will be hereinafter set forth. A baille portion prevents cornmunication between the ports 44 and 50.

At a predetermined point below the nut 38 the tubing is provided with a tubing catcher 52 (Fig. l-B), comprising an annular weighted member 54 having tapered upper side walls 56 cooperating with a pair of annular tapered slips 58 supported in inoperative position on an annular flange 60 of member 54. The member 54 is in turn supported on a helical spring 62 disposed around the tubing 4 and having its lower end` anchored to a collar 64 fixed to the tubing 4. In running the tubing -stringin the well the slips 58 are spaced from and do not vcontact the inner periphery of the casing 2. However, when `it is desired to set the tubing stringin the well at a predetermined position in proximity of the oil bearing strata or shot hole, a reciprocation of the tubing causes a simultaneous contraction and expansion of the resilient spring 62 which effects an upward movement of the member 54 causing the slips to engage with the casing 2 and set the tubing string in the well.

It will be apparent that the lowermost end of the oil Flowing from the sand into the tubing 4.

A valve unit is arranged in the tubing 4 below the nozzle 66 and is constructed similar to the valve 24 in the uppermost section of the tubing.

The valve unit (Fig. l-C) comprises a collar 70 connecting a section of the tubing 4 with a nut 1E to which is threaded valve cage '|4 encircling ball valve 16 cooperating with seat 18. Tension is applied against the ball T8 by means of an adjustable unit comprising a helical spring 82 anchored between the upper and lower plates 84 and 86 respectively. The lower plate contacts ball i5. Adjustability is provided by a threaded screw 88 arranged in the top of vthe cage '14 and contacting the upper plate 84.

A section of the tubing extends from nut 12 into connection with a collar 90 having diametrically opposed outward projections 92 provided with threaded apertures 94 for receiving valves 9G of the ball type. In the present instancey two Valves are preferab-ly used; however, it will be understood that any number of apertures and valves may be utilized in the collar. The valves 96 act as inlet valves for the oil to be lifted and are identical in structure with the valves I8 in the uppermost sections of the tubing.

Referring to Fig. 6 showing a valve in detail, it comprises an externally threaded cylinder 98 formed with a small bore |00 communicating with a larger bore |02. A ball |04 is disposed in bore |02 and allows flow of motive iluid present in the casing through a Valve i8 while both upper and lower valves act as a check for the liquid inthe tubing by seating the ball against one end of the bore |80. A single rib or baffle |06 retains the ball in the bore |02. The tubing extends from collar 90 to a point in the well where it is closed off by a conventional bull plug |08 threaded in the lower end thereof.

Referring now to the automatic intermitting apparatus comprising units A and B, the apparatus is substantially identical with that disclosed in applicants co-pending application heretofore mentioned, but in addition includes the auxiliary valve unit A for a purpose as will be hereinafter set forth.

The collar 30 (Fig. l-A) has a central body portion ||0 provided with a longitudinal bore 2. A cylindrical valve sleeve I4 is tted (preferably by sweating) in the bore H2 and is maintained by a lock nut |6. The sleeve is adapted to receive a valve ||8 comprising a freely movable shaft having a central bore |20 (shown in dotted lines) formed through its longitudinal axis. The lowerrnost end of the valve extends through the sleeve I4 into threaded engagement with the ball coupling joint |22. Although n-ot shown in the present application, but clearly explained in the co-pending application, the lowermost portion of the bore |20 is of increased diameter for housing a small spring actuated check valve to check the inflow of gas as will be hereinafter explained. The collar 30 is provided with a radial bore or pcrt |24 providing communication between the ports 34 and 40. The bore |24 communicates with diametrically opposed ports |24 through the ports |26 and around the valve' into the port 40 receiving the extension of small. 'I'he bore |20 is in communication withV tubing 6. port I 24 through a small passageway |30 adapted when the valve is in lowermost position to com-.f

municate with an annular grooved portion |32y provided in valve IIB, which in turn is provided with a small radial port (not shown). It will be understood that this construction allows communication between bore and port |24 regardless of the angular position of the valve II8.

The lowermost portion of the valve has a stop collar |34 xed thereto to limit the upstroke of the valve shaft in actual operation and to assure proper alignment of the inlet gas ports as will be hereinafter set forth. The ball joint or flexible unit |22 comprises a flanged nut |36 secured to the lower end of the valve shaft and having the flange connected to a cylindrical housing |38 in which is disposed an apertured member |40 having a semi-spherical projection |42 cooperating with complementary semi-spherical recess in the lower face of the nut I 22. A spring |44 encircles the member |40 and urges it into contact with the nut |22. It will be understood that the nut |36 and member |40 are provided with aligned bores or apertures to provide communication of the inlet gas with a threaded sleeve |46 connecting the flexible union |22 with a cylindrical float member |48.

The auxiliary valve unit A shown above the intermitting unit B is disposed between collars |52 and |54 connecting sections of tubing 4. The valve comprises a collar |56 having a central longitudinal bore |58 in which is disposed a circular valve shaft 60. The lower end of the shaft is threadedly connected by nut |62 to the intermitting valve I I8 and is adapted to move through the bore |58 in cooperation with the valve I I8 as will be hereinafter set forth. The collar |56 is provided with a smaller longitudinal bore or port |64 bailled from bore |58 and extending upward into communication with a horizontally disposed bore |66 provided in the collar |56 which provides communication with bore |64 and a second longitudinal port |68 extending from port |66 to the top of the collar.

A small bleeder port |61 (preferably le of an inch) extends upward in the collar from port |64. The ports |61 and |68 communicate with threaded recesses |10 and |12 respectively, which in turn receive apertured choke members |14 and |16 respectively for a purpose as will be hereinafter set forth. The valve shaft |60 is provided with a reduced annular portion |18 for a purpose as will be hereinafter explained. The auxiliary unit A is preferably disposed six feet above unit B, but not limited thereto.

Referring to Fig. 4, it is to be noted that the collar 30 is provided with semi-circular ports |80 acting as outlets for the lifted fluid upwardly through the eduction string 4. These ports |80 are baffled off from port |24 by a central body portion |82.

Alluding to the float |48, it is preferably comprised of le inch boiler sheet metal pipe and is approximately two inches in diameter by six feet in length, but not limited thereto. The lowermost portion of the float has longitudinal ribs |49 to keep it in proper alignment with respect to the inner periphery of the tubing 4. It will be apparent that the space between the float |48 and tubing 4 is suillcientv to allow passage of motive fluid past the float cylinder |48 without any upward lift thereof as will be hereinafter set forth. Furthermore, the ball coupling |22 assures free movement of the valve shaft II8 regardless of any possible distorted alignment of the float I 48. The float is extremely light, but since the internal pressure of the float and that of space |44 are equal, there is no danger of crushing the oat.

Operation In wells producing a high gas-oil ratio, the gas, due to its lighter density, will flo-w from the oil and gas bearing strata much more rapidly into the well hole. Furthermore, in some instances the ratio of gas is such that the sand is discharging a much greater percentage of gas than oil. In this condition the present invention allows expansion of the discharging gas upwardly in the annular space 8 between the tubing and the casing throughout the complete length of the well hole, it being understood that there are no packers or baille members in the well hole, the well being only packed oil' Iat the surface thereof. Upon expansion of the gas in the uppermost portions of the space 8 there is an increase in volume creating a change in pressure and temperature to cause a condensation of the liquiilable constituents contained in the gas, which, upon condensation, will fall back into the lowermcst portions of the well hole and build up a hydrostatic head of liquid. In many wells the condensed liquifiable constituents of the gas substantially provide -all of the column of iluid to be lifted; however, it will be understood that any liquid flowing from the sand cooperates with the condensates to provide a hydrostatic head of liquid. As the lighter liquids condense, gas remaining in the uppermost portions is directed through the slots or ports 1 of the tubing 6 for use as motive fluid for actuation of the lifting apparatus. It will be understood that the present invention is not limited to the use of gaseous pressure from the well as motive fluid, but may utilize extraneous motive fluid from the surface of the well in any conventional manner.

With a sufficient hydrostatic head of fluid built up in the space 8 such fluid is discharged through the check valve 96, ball valves 16, upwardly past nozzle 66, nut 38 until it reaches a level in the interior of the tubing substantially in proximity of the float cylinder |48. As long as the oil to be lifted is below the lowermost end of the iloat the valve I I8 is in inoperative position in that the nut |62 is abutting the top face of cylindrical seat I I4. In this position (not shown) the annular groove |32 is in alignment with the ports |30 allowing discharge of motive uid from tubing 6, ports 34 and |24, into the longitudinal bore |20 of valve I I8. This fluid is of suilicient pressure to unseat the small check valve (not sho-wn) in bore |20 and flow into the interior of the float |48. The small dimension of the bore |20 does not allow for any large volume of gas to pass through the float into contact with the oil standing below. Consequently, there is no detrimental effect against the back pressure of the well lifting the oil. With the valve in this inoperative position motive fluid flowing into the float passes beneath the bottom end thereof and upward through the space |50, ports |80, b-ore |64, continuous bleeder |61 and choke |14 upwardly through the eduction tubing 4. It will be understood in this position the reduced portion |18 of valve shaft |60 isoutl of alignment with the horizontal port |65. The arrangement of the collar |56 and its cooperating valve shaft |65 is such that in inoperative position it precludes the possibility of liquid emitting upwardly through the tubing for any reason whatsoever until the column of liquid and the increased density of the gas flowing into the cylinder |48 causes the cylinder to oat `and provide a simultaneous operation of valves |28 and |60. The construction of the apparatus is such as to provide suflicient space for passage of this small amount of gas without any possibility of .lifting the float |43 thus moving the valves H8 and it@ out of alignment with respect to ports |24 andl |65 respectively.

With an increase of the hydrostatic head of liquid to a point above the bottom end of the float |48, the float not being buoyant will submerge into the oil. However, in this condition the liquid acts as a stopper or cork forthe open end of the float so that the motive huid emitting from bore |29 and directed into the interior of the float is prevented from passing around the bottom end thereof. In this condition the interior of the oat provides a limited space or volume for the small amount of motive fluid discharging therein, and with the continued discharge from bore l', it will be apparent that the density and pressure of the gas will increase suicientiy to give a buoyant effect to the cylinder |48 and cause it to float in the liquid pool, thereby moving it upwardly in a vertical path. Upward vertical movement of the cylinder |48 causes a simultaneous upward movement of the valves H3 and les to a point where the reduced portion |28 of valve I8 is in alignment with port |24, and reduced portion |'l8 of valve lll is in alignment with port |55. The stop collar |34 limits the vertical upward travel of the valves to assure proper alignment.

In this operative position of the valve shafts, motive fluid is directed from tubing 5, port |24, around reduced portion |28 into ports 4Q, 42, the lowermost sections of tubing 6, to be jetted outwardly from the nozzle aperture S8. With the outward discharge of motive fluid pressure in an upstream direction into the column of liquid standing in the tubing, the liquid is lifted in the eduction tubing through ports |33, bores |35, |62?, |58, apertured choke ll, through ball valve 21| on to the top of the well. The bore in choke |'i5 is smaller in diameter than port |53 and pre* vents any cutting action at the valve due to pressure. Motive fluid present in the uppermost sections of the well is allowed to iiow through check valve i3 for boosting or assisting the lifting of the liquid column by the motive iiuid emitting from nozzle 58. Furthermore, the pressure and speed of the motive fluid displaces the oil through the eduction tubing with such velocity as to substantially eliminate paraflin deposits in the tubing. It will be apparent that the oat cylinder |43 will maintain the valves H and |55` in an upward or operative position as long as the cylinder |40 floats. The valve l i8 is balanced since it is the same diameter on both sides of the main port |25. Furthermore, the collar |53 can be provided with horizontally disposed ports (not shown) arranged on both sides of port It in order to allow induction of outside gas pressure for balancing the valve ll as well as keeping it clean of sand and other detrimental elements.

With the oil displaced in the tubing above the bottom end of float cylinder |48, the supply gas contained therein'escapes and the float cylinder moves the valves H8 and |69 downward to a position where the nut |62 abuts the top of the seat H4. In this position the motive fluid is then directed through bore |20 into cylinder |48 where it is discharged up through the eduction tubing until such time as the liquid level is raised to float the cylinder |48.

The valves 9B by a restricted opening act as a choke to provide the proper gas-oil ratio in the tubing, because, if such restriction were not present in wells having tremendous .gas pressure, gas would be induced in the tubing 4 to continuously slug the oil upward regardlessv of any change in density of gas in the' float cylinder |48 and the intermitting effect desired. The bleeder port Il allows emission of gas up the tubing 4 to prevent a pressure condition within the cylinder |48 equal to that of space 8 thereby assuring intermittent action 'of the float cylinder. The adjustable valve unit applies tension through spring 82 to assure that the pressure inside the tubing 4 is always less than' that of the outside, thus preventing any balancing of pressures and assure that'the motive fluid can ilo'w into the float cylinder to assure the intermitting action.

From the foregoing it will be apparent that the automatic intermitting apparatus is arranged in the well hole in order to allow expansion of pressure gas from the well into the uppermost sections of the well thereby creating a condensation of the liquiable constituents of the ga's to provide a submergence level which acts as a stopper for the oat cylinder thus making it capable oi having buoyant characteristics by increasing the density of the input motive uid therein and causing an upward movement of the cylinder for actuating the intermitting valve and its auxiliary choke valve to allow input motive fluid to be ietted into the liquid column below the float cylinder. l Furthermore, the device precludes the possibility of continuous slugging of the oil in wells having tremendous gas pressures in that the auxiliary valve chokes off the' flow of oil upward in the eduction tubing thus assuring an intermittent action in lifting the oil.' The apparatus is automatic in its operation in that no extraneous time controlled mechanism is necessary, and the time interval for the intermittent operation of the automatic valve unit can be determined by known dimensions and the bottom hole pressure of the well. it will be apparent that the device is simple and eiicient in its operation and assures an intermittent action for slugging the column of liquid under any well condition. The working parts are easily assem'- bled and synergetic in their relations to one another. i

Changes may be made in the combination and arrangement of parts as heretofore set forth in the speciiication and shown in the drawings, it being understood that any modification in the precise embodiment'of the Ainvention may be made within the scopev of the following claims without departing from the spirit of the inven tion.

What I claim is:

l. In a pressure fluid lifting apparatus disposed in the eduction tubing of a well, a Valve collar interposed in the tubing, a movable inlet valve arranged therein, open ended means movable to sink and float in the liquid being lifted, said means operably cooperating with the valve whereby oating of the means will move the valve to flow inlet pressure fluid therethrough into the eduction tubing for displacing the liquid, and means precluding the flow of liquid from the well until flowing of pressure fluid through the inlet valve.

2. In a pressure fluid lifting apparatus disposed in the eduction tubing of a well, a movable inlet valve arranged in the tubing, a cylinder flexibly connected to said valve, means providing inlet fluid communication between the valve and the cylinder, said cylinder responsive to the liquid level in the well and the density of the pressure fluid in the cylinder to acquire buoyancy and move the valve whereby inlet fluid is passed therethrough into the eduction tubing for lifting the liquid, and means for precluding the flow of liquid from the well until the flowing of inlet fluid through the valve.

3. In a pressure fluid lifting apparatus disposed in the eduction tubing of a well, a movable inlet Valve arranged in the tubing, operating means flexibly connected to the said valve, means providing inlet pressure communication between the valve and the operating means, said operating means responsive to the liquid level and the density of the pressure fluid in the operating means to provide buoyant characteristics to the operating means whereby the valve is moved to allow inlet pressure fluid to flow therethrough into the eduction tubing for displacing the liquid, and means for precluding the flow of liquid from the well until flowing of inlet pressure fluid through the valve.

4. A pressure fluid lifting apparatus disposed in the eduction tubing of a well, a movable inlet valve arranged in the tubing, an open ended cylinder flexibly connected to said valve, means providing inlet fluid communication between the valve and the cylinder, said cylinder responsive to the liquid level to provide a chamber maintaining inlet pressure fluid therein, said pressure fluid emitting from the valve into the chamber to effect a buoyancy to the cylinder whereby the valve is moved to flow pressure fluid therethrough into the eduction tubing at a point below the liquid level, and means for precluding the flow of liquid from the well until the flow of pressure fluid through the valve.

5. In a pressure fluid lifting apparatus disposed in the eduction tubing of a well, a valve collar, a

movable inlet valve arranged therein, a complementary choke valve arranged above the inlet valve and simultaneously movable therewith, open ended means movable to sink and float in the liquid to be lifted, said means operably cooperating with the inlet Valve whereby floating of the means will move the inlet valve to flow inlet fluid therethrough, and means for jetting the pressure fluid passing through the inlet valve in an upstream direction into the eduction tubing for displacing the liquid therefrom, said complementary valve precluding flow of liquid from the well until flowing of the pressure fluid through the inlet valve.

6. In an automatic intermitting system for lifting liquid from a well comprising an eduction tubing having a pressure lifting apparatus arranged therein, said apparatus adapted to allow expansion of pressuregas from the well to effect separation of the liquifiable constituents by condensation to provide a head of liquid in the well, a valve collar arranged in the apparatus and having a movable inlet valve disposed therein, open endedmeans movable to sink and floatJ in the condensates to be lifted, said means cooperating with the inlet valve whereby floating of the means Will move the Valve to allow passage of in- -let pressure fluid therethrough into the eduction tubing for displacing the condensates.

'7. In an automatic intermitting system for lifting liquid from a well comprising an eduction tubing having a pressure lifting apparatus arranged therein, said apparatus adapted to allow expansion of pressure gas from the well to effect separation of the liquifiable constituents by condensation to provide a head of liquid in the well, a valve collar arranged in the apparatus and having a movable inlet valve disposed therein, open ended means movable to sink and float in the condensates to be lifted, said means cooperating with the inlet valve whereby floating of the means will move the Valve to allow passage of inlet pressure fluid therethrough'yinto the eduction tubing for displacing the condensates, and means precluding the flow of liquid from the well until the passage of inlet pressure fluid through the valve.

8. In a well pumping apparatus, a well bore, an eduction tubing string arranged in the bore for conducting liquid from the well to the top of the latter, means in the tubing string to obstruct the flow of liquid therethrough, a passage-way in said means terminating in a choke, a valve controlling the passage of well fluid through said passageway and choke, and a float in the tubing string arranged below said choke and operatively connected with the Valve for controlling the latter.

9. In a well pumping apparatus, a well bore, an eduction tubing string arranged in the bore for conducting liquid from the well to the top of the latter, means in the tubing string to obstruct the flow of liquid therethrough, a passage-way in said means terminating in a choke, a valve controlling the passage of well fluid through said passageway and choke, a float in the tubing string arranged below said choke, and operatively connected with the valve for controlling the latter, and a loaded check valve arranged in the tubing string below the float for controlling the flow of liquid into the portion of the tubing string where the float is positioned.

10. In a well pumping apparatus, a well bore, an eduction tubing string arranged in the bore for conducting liquid from the well to the top of the latter, means in the tubing string to obstruct the flow of liquid therethrough, a passage-way in said means terminating in a choke, a valve controlling the passage of well fluid through said 

